High-energy and very high-energy gamma-ray emission from the magnetar SGR 1900+14 outskirts

Discussion timeslot (ZOOM-Meeting): 14. July 2021 - 18:00
ZOOM-Meeting URL: https://desy.zoom.us/j/98542982538
ZOOM-Meeting ID: 98542982538
ZOOM-Meeting Passcode: ICRC2021
Corresponding Session: https://icrc2021-venue.desy.de/channel/47-The-central-engines-of-fast-transients-Gamma-Ray-Bursts-and-Fast-Radio-Bursts-GAD-GAI-MM/112
Live-Stream URL: https://icrc2021-venue.desy.de/livestream/Discussion-04/5

Abstract:
"One of the unsolved problems in cosmic ray (CR) physics is the determination of sources and acceleration mechanism(s) of Galactic ($Elesssim 10^{18}$) eV and extragalactic ($Egtrsim 10^{17}$ eV) CR . Ultra high energy CR (UHECR, $E>10^{18}$ eV) are believed to be of extragalactic origin,  but some contribution from transient Galactic sources is possible. So, magnetar wind nebulae (MWNe), created by new-born millisecond magnetars, and magnetar giant flares are PeVatron candidates and  even potential sources of  UHECR. Promising signature of effective acceleration processes in magnetars' neighbourhoods should be  a nonthermal high-energy  and very high-energy $gamma$-ray emission according to pp collisions with a subsequent pion decay (hadronic scenario) and inverse Compton scattering of low energy background photons by ultrarelativistic electrons and positrons  (leptonic scenario). In this work we explain a  HE and VHE $gamma$-ray emission from the vicinity of the magnetar SGR 1900+14 -- potential Galactic source of $E>10^{20}$ eV triplet --  by hadronic and leptonic emission of cosmic rays accelerated in a magnetar-related  Supernova remnant (SNR) and/or MWN. To this end we carried out a simulation of the observed  HE  and VHE  $gamma$-ray emission, spatially coincident with the magnetar SGR 1900+14. The  extended {it Fermi}-LAT source 4FGL J1908.6+0915e,  the extended H.E.S.S. source candidate HOTS J1907+091 and the point-like HAWC  TeV source 3HWC J1907+085 were considered. We show that  the observed $gamma$-ray emission from the magnetar SGR 1900+14 outskirts  may be explained by a (still undetected) magnetar-connected super-luminous Supernova (Hypernova) remnant and/or a MWN created by new-born millisecond magnetar with a large initial rotational energy $E_{textrm{textrm{rot}}}sim 10^{52}textrm{ erg}$."

Authors: Bohdan Hnatyk | Vadym Voitsekhovskyi | Roman Hnatyk | Valery Zhdanov
Indico-ID: 437
Proceeding URL: https://pos.sissa.it/395/672